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Get Census Tract Demographics Integrate Demographic Data into Shapefile Set Thematic Map Properties View Thematic Map Adding Labels Adding Streets Geodemographics WebCourse |
Census Tract Demographics -- information resources for census tracts: demographic, social, economic, & housing
Install the no-fee CommunityViewer GIS software (CV1 -- registration required). The remainder of this section is a tutorial/demonstration. After installing the CV software, you can proceed through these or similar steps to develop maps of interest to you. In this example, the objective is to develop a thematic map of percent population in poverty for Hawaii by census tract. Get Census Tract Map File Start CV. Use File>Open to open the project c:\cv1\mapfiles\us.gpr. This project is developed as described in the CV applications guide and contains only the U.S. by state shapefile. Zoom to full extent and zoom in to Hawaii. Navigate to this view of Honolulu County. 
Use File>GetWebGeodata. Select Hawaii Census Tracts and click Get File. 
Messages appear confirming download success and files ready to use. Close the WebGeodata panel. Use the Add layers button on the toolbar. Add the layer (shapefile) just downloaded (c:\cv1\mapfiles\tr15_d00.shp). 
Use File>Save ProjectAs to save the project as c:\cv1\mapfiles\hitracts.gpr. Leave CV running (optionally close and re-open later). Next get the census tract demographics. Get Census Tract Demographics Start a Web browser and open the URL http://factfinder.census.gov. Select Dataset Click Data Sets button in left column. On the next page, click Census 2000 Summary File 3 radiobutton. On the same page, click Detailed Tables in right column. Select Geography On the next page, click 'geo within geo' button. Select Census Tracts in 'Show me all' selection box. Select State in 'Within' selection box. Select Hawaii in 'Select a state' selection box. Click on 'All Census tracts' in 'Select one or more geographic ...' selection box. Click the Add button. Click the Show Result button. Select Subject Matter Select Table PCT49 in 'Select one or more tables ...' Click the Add button. Click the Show Result button. Save data file to your computer Click the Download button as shown in graphic below. 
Click Microsoft Excel button on next panel. Click OK on same panel. As file open prompt appears, click Open. Save the last file in the list (see below) as c:\cv1\mapfiles\m15000t_sf3_pct49.xls). 
The Excel file is now on your computer. You can open this file using Excel or any software that will read and Excel file. Integrate Demographic Data into Shapefile Return to the CV window. Use File>Open to open the Hawaii by census tracts shapefile (c:\cv1\mapfiles\tr15_d00.shp). Click the Hawaii by tracts layer name (tr15_d00.shp) in the legend panel (at left). It turns blue. If the Excel file is open by another program, close it. On the main menu, click Database>TractDemographics. Reply yes to 'Is the correct layer active?' (the tracts layer name must be blue). Select the Excel file to integrate (c:\cv1\mapfiles\m15000t_sf3_pct49.xls). Reply Yes to the confirmation message is correct. Processing takes place, requiring possibly a minute. The mesaage 'Tract demographics processing done' appears. Use File>Open to open the project c:\cv1\mapfiles\hitracts.gpr. Set Thematic Map Properties Using the layer editor, sections (data intervals) will be specified for three levels of percent population in poverty. The percent of population in poverty is computed from data in the Excel file by dividing PCT049002 by PCT049001. 
Dbl-click the layer name tr15_d00.shp and the layer editor panel opens. Define the data interval bounds Select the Section tab. Key in the section query statement: 100*PCT049002/PCT049001<7. Key in the section (interval) legend name: Less than 7% Click 'include in legend' checkbox 
Click the + button below the above panel to add another section. Two more sections are added. Next (second) section: Key in the section query statement: 100*PCT049002/PCT049001>=7 and 100*PCT049001/PCT049002<20. Key in the section (interval) legend name: 7% to 20% Click 'include in legend' checkbox Next (third) section: Key in the section query statement: 100*PCT049002/PCT049001>20. Key in the section (interval) legend name: 20% or more. Select color/fill patterns for each interval Click the Area tab and the first section (visible query statement). Change the Pattern to SOLID and the Color to green. Click 'include in legend' checkbox Click on the next Visible Query section and change it to SOLID and yellow. Click on the next Visible Query section and change it to SOLID and red. 
Click the layer editor Layer tab. Change the caption to '%Pop in Pov by Tract'. 
To set the background color (ocean) to blue, use File>Edit project file. Find [R0001GIS] statement toward bottom and change: 'BackgroundColor=white' to 'BackgroundColor=blue' Click disk icon at left. Use File>Save As to save the project as c:\cv1\mapfiles\hitracts1.gpr. 
Thematic Map Results Honolulu, HI by Census Tract -- Percent Population in Poverty by Census Tract 
Label Tracts with Percent in Poverty Greater than 20% Navigate to Diamondhead area (lower right). Dbl-click tract layer name in legend panel to invoke editor. Select Label tab. Select TRACT as field only for section 3. Select Label>Position. Set label position to center. Click Apply and OK. 
Resulting map appears as shown below. The identify tool is used to click on tract 21 (0021). The total population (for whom poverty status determined) is 3,502. It can be observed that the percent population in poverty is 20.45 percent (computed as PCT049002 (716 persons) divided by PCT04901 (3502 persons)). This value is just above the lower end of the 'higher poverty' interval. 
Adding Streets Get the TIGER/Line File for Honolulu County (15003) using the GetWebGeodata. 
Reply no at the prompt 'Build project?'. Use the Add layers button to add the TIGER/Line file c:\cv1\mapfiles\tgr15003.rt1. Use the File>Export to export this file to a shapefile that has only streets (query statement CFCC LIKE 'A%'). 
Click OK and save the file in the save dialog as c:\cv1\mapfiles\m15003r.shp. Zoom to right-center area of tract 21. Add c:\cv1\mapfiles\m15003r.shp streets layer. Click off the tgr15003.rt1 layer. Dbl-click this layer name and add label using field name FENAME and set position to Follow. Click Add and OK. Street names now appear as shown in graphic below. Click segment of Kapahulu as shown in map. The profile shows the street address range on the right and left side of the street segment. Navigate further down in the profile and see that the tract code on the left side of the segment is 2100 and the tract code on the right side of the segment is 1500. This segment is a boundary between census blocks 2100-1007 and 1500-1003. 
Use File>Save ProjectAs to save the project as c:\cv1\hitracts3.gpr. goto top |
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